NUMBER OF METASTABLE STATES OF A CHAIN WITH COMPETING AND ANHARMONIC PHI-4-LIKE INTERACTIONS

We investigate the number of metastable configurations of a PHI4-like model with competing and anharmonic interactions as a function of an e ffective coupling constant eta. The model has piecewise harmonic neare st-neighbor and harmonic next-nearest-neighbor interactions. The numbe r M of metastable states in the configuration space increases exponent ially with the number N of particles: M is-proportional-to exp(nuN). I t is shown numerically that, outside the previously considered range A bsolute value of eta < 1/3, nu is approximately linearly de creasing w ith eta for Absolute value of eta < 1 and that nu = 0 for eta greater- than-or-equal-to 1. These findings can be understood by describing the metastable configurations as an arrangement of kink solitons whose wi dth increases with eta.